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//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
// UNSUPPORTED: c++03, c++11, c++14, c++17, c++20
// <string>
// template<class Operation>
// void resize_and_overwrite(size_type n, Operation op)
#include <algorithm>
#include <cassert>
#include <string>
#include "make_string.h"
#include "test_macros.h"
template <class S>
constexpr void test_appending(size_t k, size_t N, size_t new_capacity) {
assert(N > k);
assert(new_capacity >= N);
auto s = S(k, 'a');
s.resize_and_overwrite(new_capacity, [&](auto* p, auto n) {
assert(n == new_capacity);
LIBCPP_ASSERT(s.size() == new_capacity);
LIBCPP_ASSERT(s.begin().base() == p);
assert(std::all_of(p, p + k, [](const auto ch) { return ch == 'a'; }));
std::fill(p + k, p + n, 'b');
p[n] = 'c'; // will be overwritten
return N;
});
const S expected = S(k, 'a') + S(N - k, 'b');
assert(s == expected);
assert(s.c_str()[N] == '\0');
}
template <class S>
constexpr void test_truncating(size_t o, size_t N) {
assert(N < o);
auto s = S(o, 'a');
s.resize_and_overwrite(N, [&](auto* p, auto n) {
assert(n == N);
LIBCPP_ASSERT(s.size() == n);
LIBCPP_ASSERT(s.begin().base() == p);
assert(std::all_of(p, p + n, [](auto ch) { return ch == 'a'; }));
p[n - 1] = 'b';
p[n] = 'c'; // will be overwritten
return n;
});
const S expected = S(N - 1, 'a') + S(1, 'b');
assert(s == expected);
assert(s.c_str()[N] == '\0');
}
template <class CharT>
constexpr bool test() {
using S = std::basic_string<CharT>;
test_appending<S>(10, 15, 15);
test_appending<S>(10, 15, 20);
test_appending<S>(10, 40, 40);
test_appending<S>(10, 40, 50);
test_appending<S>(30, 35, 35);
test_appending<S>(30, 35, 45);
test_appending<S>(10, 15, 30);
test_truncating<S>(15, 10);
test_truncating<S>(40, 35);
test_truncating<S>(40, 10);
return true;
}
void test_value_categories() {
std::string s;
s.resize_and_overwrite(10, [](char*&&, size_t&&) { return 0; });
s.resize_and_overwrite(10, [](char* const&, const size_t&) { return 0; });
struct RefQualified {
int operator()(char*, size_t) && { return 0; }
};
s.resize_and_overwrite(10, RefQualified{});
}
int main(int, char**) {
test<char>();
test<char8_t>();
test<char16_t>();
test<char32_t>();
#if defined(__cpp_lib_constexpr_string) && __cpp_lib_constexpr_string >= 201907L
static_assert(test<char>());
static_assert(test<char8_t>());
static_assert(test<char16_t>());
static_assert(test<char32_t>());
#endif
#ifndef TEST_HAS_NO_WIDE_CHARACTERS
test<wchar_t>();
#if defined(__cpp_lib_constexpr_string) && __cpp_lib_constexpr_string >= 201907L
static_assert(test<wchar_t>());
#endif
#endif
return 0;
}
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